A custom pirsch.js without the requirement for a script tag in the header section.

pirsch-no-script-tag.js

(function () {
    "use strict";

    // The identification code for your website from the settings page.
    // Required.
    const identificationCode = "";

    // A comma-separated list of path patterns (regular expressions) to include.
    // Optional.
    const includePaths = "";

    // A comma-separated list of path patterns (regular expressions) to exclude.
    // Optional.
    const excludePaths = "";

    // A comma-separated of domains to send page views to. This can be used to create roll-up views.
    // Optional.
    const domainList = "";

    if (navigator.doNotTrack === "1" || localStorage.getItem("disable_pirsch")) {
        return;
    }

    if ((/^localhost(.*)$|^127(\.[0-9]{1,3}){3}$/is.test(location.hostname) || location.protocol === "file:")) {
        console.warn("Pirsch ignores hits on localhost. You can enable it by adding the data-dev attribute.");
        return;
    }

    try {
        const paths = includePaths ? includePaths.split(",") : [];

        if (paths.length) {
            let found = false;

            for (let i = 0; i < paths.length; i++) {
                if (new RegExp(paths[i]).test(location.pathname)) {
                    found = true;
                    break;
                }
            }

            if (!found) {
                return;
            }
        }
    } catch (e) {
        console.error(e);
    }

    try {
        const paths = excludePaths ? excludePaths.split(",") : [];

        for (let i = 0; i < paths.length; i++) {
            if (new RegExp(paths[i]).test(location.pathname)) {
                return;
            }
        }
    } catch (e) {
        console.error(e);
    }

    const domains = domainList ? domainList.split(",") || [] : [];

    function hit() {
        sendHit();

        for (let i = 0; i < domains.length; i++) {
            sendHit(domains[i]);
        }
    }

    function sendHit(hostname) {
        if (!hostname) {
            hostname = location.href;
        } else {
            hostname = location.href.replace(location.hostname, hostname);
        }

        const url = "https://api.pirsch.io/hit" +
            "?nc=" + new Date().getTime() +
            "&code=" + identificationCode +
            "&url=" + encodeURIComponent(hostname.substring(0, 1800)) +
            "&t=" + encodeURIComponent(document.title) +
            "&ref=" + encodeURIComponent(document.referrer) +
            "&w=" + screen.width +
            "&h=" + screen.height;
        const req = new XMLHttpRequest();
        req.open("GET", url);
        req.send();
    }

    if (history.pushState) {
        const pushState = history["pushState"];

        history.pushState = function () {
            pushState.apply(this, arguments);
            hit();
        }

        window.addEventListener("popstate", hit);
    }

    if (!document.body) {
        window.addEventListener("DOMContentLoaded", hit);
    } else {
        hit();
    }
})();